The last time Sebastian Vettel entered a new season with a highly-rated young newcomer alongside him, he left the team where he had been established at the end of the year. While Vettel claimed he was "not running away from anything" when he chose to depart Red Bull in 2014, it was clear to others in Formula 1 - including his own team boss, Christian Horner - that his drubbing by Daniel Ricciardo after winning four titles in a row had played a part.
That is why so many people are now drawing parallels between that season and this one, which will mark Vettel's fifth at Ferrari since exiting Red Bull and kicks off next weekend with Charles Leclerc alongside him at the Maranello team. The challenge Leclerc could pose Vettel is significant. It's one that Vettel is not underestimating but plenty have been guilty of over-egging.
In some ways, Leclerc is indeed Vettel's worst nightmare. He's the reason people are asking if Vettel will be forced out of Ferrari, like many believe Ricciardo did to him at Red Bull.